Three Poster Presentations Scheduled for Society for Immunotherapy of
Cancer Annual Meeting

November 11, 2016 11:59 AM Eastern Time

EAGAN, Minn.--(EON: Enhanced Online News)--Biothera Pharmaceuticals, Inc. will present new preclinical data today
that further validate the ability of its Phase 2 cancer immunotherapy
drug Imprime PGG to induce coordinated innate and adaptive immune
responses that may enhance the efficacy of checkpoint inhibitor
therapies. The data will be highlighted in three poster presentations,
including one late-breaking poster, at the annual meeting of the Society
for Immunotherapy of Cancer (SITC) in National Harbor, MD, November
11-13, 2016.

“The data presented at SITC further elucidate the ability of Imprime PGG
to trigger the changes across the immune system that enable a
coordinated, anti-cancer immune response”

The new findings in several in vivo preclinical models confirm
earlier in vitro research that show Imprime PGG administration
activates critical cross-talk between the innate immune effector cells
and the adaptive immune system, driving cytotoxic T cell expansion and
the production of anti-tumor cytokines. The data also show that Imprime
PGG “flips” the suppressive immune microenvironment of the tumor to an
environment that promotes immune recognition and destruction of the
tumor. These effects were associated with changes in biomarkers and
immune cell types at the tumor site, as observed using
immunohistochemistry and algorithm-based analysis. Biothera will
continue to apply this technology in upcoming Phase 2 clinical studies
to analyze tumor biopsies for changes in the tumor microenvironment.

“The data presented at SITC further elucidate the ability of Imprime PGG
to trigger the changes across the immune system that enable a
coordinated, anti-cancer immune response,” said Jeremy Graff, Ph.D.,
Biothera Pharmaceuticals Chief Scientific Officer and Senior Vice
President, Research. “Importantly, we can show now these changes at the
tumor site using the same technology to be used in our upcoming clinical
trials.”

Imprime PGG is a Pathogen Associated Molecular Patterning (PAMP)
molecule that acts therapeutically as an immunological “ignition switch”
to activate a number of innate immune functions that then drive a
coordinated anti-cancer immune attack in combination with immune
checkpoint inhibitors, anti-angiogenic and tumor targeting antibodies.
Biothera Pharmaceuticals and Merck are advancing a phase 2 clinical research
collaboration to evaluate Imprime PGG and Merck’s anti-PD-1
inhibitor KEYTRUDA® (pembrolizumab) in patients with either
advanced melanoma or metastatic triple negative breast cancer. The
Companies are also collaborating with the Big Ten Cancer Research
Consortium to commence an Imprime PGG plus KEYTRUDA Phase 1b/2 study
in patients with non-small cell lung cancer (NSCLC).

About Biothera Pharmaceuticals, Inc.Biothera
Pharmaceuticals is a privately held biotechnology company developing
Imprime PGG, a mid-clinical stage cancer immunotherapy that orchestrates
an integrated anti-cancer immune response in combination with checkpoint
inhibitors, as well as tumor-targeting and anti-angiogenesis monoclonal
antibodies. Imprime PGG has been well-tolerated in trials in over 400
subjects and has established proof of concept in multiple clinical
studies, including single-arm and randomized phase 2 studies in NSCLC,
colorectal cancer, and chronic lymphocytic leukemia.